Propylene is a key petrochemical intermediate, with fluidized-bed propane dehydrogenation (PDH) offering advantages through enhanced heat/mass transfer and continuous operation for frequent reaction-regeneration processes. However, catalyst development faces challenges under harsh conditions including short residence times, frequent regeneration, and extensive steam exposure. This study investigates cobalt-loaded silicalite-1 (Co/S-1) catalysts engineered for prompt activation and sustained performance in fluidized PDH environments. Using comprehensive characterization techniques, we established CoOx structure-performance relationships at the early reaction stage (within a few seconds). H₂-TPR and UV-Vis spectroscopy revealed insights into structural transitions of CoOx phases under different loading conditions. Raman, FT-IR and in situ C3H8-DRIFTS analyses demonstrated the crucial role of silanol nests in anchoring isolated Co²⁺ species within the silicalite-1 framework. STEM-HAADF analysis revealed cobalt dispersion behaviors, particularly following multiple reaction-regeneration cycles. We developed an innovative oxychlorination-based regeneration strategy that effectively redistributes deactivated cobalt species and restores catalytic performance. In situ steam-DRIFTS experiments confirmed silicalite-1's exceptional steam resistance, evidenced by minimal hydroxyl adsorption and accelerated desorption kinetics. Our findings elucidate design principles for scalable, non-noble metal catalysts optimized for fluidized-bed PDH environments, advancing steam-tolerant dehydrogenation technologies.
